Im pretty sure you have to post the plugin and smx here and cannot link to some other site. Just fyi...
And, the other info about which mods and crap it works in would be nice.
EDIT: This definitely does NOT work in tf2 with 1.1.2. Im gonna guess it doesnt work period, but it may be specific to CSS. In tf2 it just made lag and some annoying repeating sound. Anyways.... CSS only maybe?